Does Occupational title matter?

Had as of now 3 instances where my neighbor wrotee a note to me to not park my car a certain time for moving purposes and signed it with DR.

Another 2 where I was taking reservations and both times the individuals refered themselves as Dr.

I don't understand the concept as to why they have to emphasize on their Occupational title. They won't get treated any different/better than anyone else (for me). Is this a superiority mentality? I personally could care less. Being capricious, I jotted the Dr.'s name as Mr. right infront of him.